Immersed pumps boiler cleaning



Aug. 19, 1969 H. c. JACKSON ETAL 3,462,302

IMMERSED PUMPS BOILER CLEANING Filed March 2, 1965 3 Sheets-Sheet 1lNVENTORs Aug. 19, 1969 H. c. JACKSON ETAL 3,462,302

IMMERSED PUMPS BOILER CLEANING Filed March 2, 1965 3 Sheets-Sheet 2 Aug.19, 1969 c, JACKSON ET AL 3,462,302

IMMERSED PUMPS BOILER CLEANING Filed March 2, 1965 5 Sheets-Sheet 5 HC.Jim/r501? M5 B. #4 (1 06K 4. W. MOPP/sav INVENTORS United States Patent0.

3,462,302 IMMERSED PUMPS BOKLER CLEANING Herbert C. Jackson, 12 GreasbyRoad, Upton, Wirral,

England; Wiiliam E. B. Havelock, 1 Fairfield Green,

West Monkseaton, Northumberland, England; and Albert W. Morrison, 14Neasdon Crescent, Tynemouth,

Northurnberland, England Filed Mar. 2, 1965, Ser. No. 436,509 Int. CE.E081) 9/06 US. Cl. 134169 4 Claims ABSTRACT OF THE DISCLOSURE Apparatusfor cleaning the internal surfaces of boilers and the like, wherein apump is mounted on a false door for the boiler and a manifold associatedwith the pump is located within the boiler. A plurality of pipes areconnected between the manifold and the portions of the boiler system tobe cleaned to provide circulation of the cleaning fluid through theportions of the boiler system to be cleaned during operation of thepump.

This invention is for improvement in or relating to the chemicalcleaning of internal surfaces. The invention is particularly, althoughnot exclusively, concerned with the chemical cleaning of boilers andother heat exchanger apparatus having internal surfaces which requirecleaning periodically to remove deposits.

In the chemical cleaning of boilers it has hitherto been customary toprovide a complicated system of external pipe lines connecting anexternal part and a sump tank to selected external points of the boilersystem so as to ensure adequate and complete circulation of the chemicalcleaning composition throughout the system. This method of chemicallycleaning a boiler requires a considerable time to set up and dismantleand so prolongs the period for which the boiler must remain out ofaction. Normally and in order to promote circulation through all partsof the boiler system the pump is arranged to introduce the chemicalcleaning fluid into the top or bottom of the boiler or other units to becleaned, the chemical cleaning fluid being returned to the sump tankthrough a number of connections on the bottom rear wall box, side wallbox, water pocket or muddrum and superheater on top of the boiler.External lines are a nuisance in boiler houses and furthermore there isa danger of the cleaning acid or other cleaning fluid leaking at pointsalong the system and doing damage to either the plant itself or to theoperatives and their clothing.

An object of the present invention is to provide a system in whichchemical cleaning of internal heating surfaces, for example boilers, iseffected Without the l1ereto fore objectionable arrangement of externallines, connection points to the boiler system, and sump tanks.

According to the present invention there is provided a method ofchemically cleaning systems or apparatus having internal surfaces (e.g.,the internal surfaces of boiler systems) which comprises introducin intothe system or apparatus, at least partially, means for circulating thechemical cleaning fluid, closing the system or apparatus and thencirculating for the required time the chemical cleaning fluid in aclosed circuit and subsequently removing the chemical cleaning fluid andthe means for circulating it.

In one convenient manner of carrying out the method according to theinvention a pump for circulating the chemical cleaning fluid isintroduced into a drum (e.g., a steam drum) at the upper part of aboiler or similar system so that the pump is wholly submerged orenclosed in the drum and serves to circulate the cleaning fluid as aPatented Aug. 19, 1969 "ice closed circuit through the boiler tubes andback into the drum. Circulation can be controlled or directed bycoupling the outlet of the pump internally, by flexible pipes, toappropriate parts of the boiler system. In one convenient arrangementthe pump is mounted on the inner face of a false door for the steamdrum, the normal door having been removed. In one preferred arrangementthe pump is driven by a pneumatic motor. In this case airlineconnections are provided on the false door or directly on the motor forconnection to compressed airlines from any convenient source which maybe either an existin compressed air supply or for example a compressedair pump or bottle.

In an alternative arrangement the pump and its driving motor arearranged externally of the drum or the like and the false door carries amanifold or the like connected to the pump and from which the chemicalcleaning fluid can be distributed to appropriate parts of the boilerorother system (e.g., by flexible pipes) when the false door is inposition and the pump in operation.

Conveniently the chemical cleaning liquid is introduced into the systemso as substantially wholly to fill the system or those parts of thesystem to be treated, the arrangement being such that a closed circuitis established over which the pump when in operation can circulate thecleaning fluid. To ensure good distribution of the chemical cleaningfluid the outlet side of the pump or if convenient the whole of the pumpmay be situated in or lead into a manifold the manifold extendingsubstantially along the length of, or along any desired length of thedrum or header tank of the system as the case may be. Thus, the cleaningfluid from the pump is delivered along the length of the manifold andconveniently spaced outlets along the manifold permit the fluid to leaveit and enter the boiler or other system at appropriate points.

If desired one or more of the outlet holes in the manifold may beconnected by, for example, flexible piping, to any required part of theboiler system so that the circulation of cleaning fluid is confined tothose particular parts of the system requiring treatment.

In cases where the pump is situated outside the boiler or other systemto be cleaned it may be mounted on the outside of a false door for adrum or header of the system. Alternatively the false door may beprovided with coupling means for two or more pipes (e.g., a feed andreturn pipe) or other conduits which connect the pump to the interior ofthe boiler system for the circulation of the cleaning fluid through theappropriate parts thereof.

In a still further arrangement where a pump is situated outside theboiler system, the door of the drum or some other convenient componentof the system is provided permanently with closable portways. With thisarrangement all that is necessary for carrying out the cleaningoperation is for the external pump to be connected by flexible pipes tosaid portways, the system filled with cleaning fluid, and the pumpoperated so as to circulate said fluid through the boiler system whilstthe pump is in operation.

Two particular embodiments of the invention will now be described by wayof example as applied to a boiler system and with reference to theaccompanying diagrammatic drawings.

On the drawings:

FIGURE 1 is a perspective view of one arrangement.

FIGURE 2 is a perspective view of the second arrangement and FIGURES 3,4 and 5 are detailed views of a false door for use in the arrangementshown in FIGURE 2.

Referring first to the embodiment of the invention shown in FIGURE 1 theboiler system comprises the steam drum 10, a lower water drum 11, sidewall mud box 12, downcomers 13, side water wall tubes 14 and rear waterwall tubes 15.

It will be appreciated that in practice the boiler system may be muchmore complex than is shown in FIGURE 1, which has been simplified forthe purpose of illustrating the invention.

For the purpose of the invention the steam drum 10, is adapted to beprovided temporarily (e.g., when cleaning is to be effected) with afalse door 16. This false door carries a pump 17 in which isincorporated a pressure fluid (e.g., pneumatic) driving motor. Intakeand exhaust pipes 18 and 19 respectively for the operation of the motorof the pump 17 are connected, by way of unions 20' and 21 on the falsedoor 16, to the motor. The pipes 18 and 19 are provided with controlvalves 18a and 19a.

The fluid circulating pump 17 includes a discharge manifold from whichcan be led a plurality of flexible tubes 22 adapted to be inserted inthe downcomers 13.

When it is required to effect cleaning of the boiler system internallythe normal door on the steam drum is removed and replaced by the falsedoor 16 so that the pump 17 is introduced into the steam drum. The tubes22 having been introduced into the appropriate downcomers the pump isset in operation so as to circulate the cleaning fluid, a supply ofwhich has been introduced into the steam drum, into the boiler system byway of the downcomers 13 and back to the drum by way of the side andrear wall tubes 14 and 15.

When cleaning of the boiler system has been completed the false door 16is removed and replaced by the normal door, the cleaning fluid havinbeen pumped or otherwise extracted from the system.

The embodiment of the invention shown in FIGURES 2, 3, 4 and is similarin some respects to that already described with reference to FIGURE 1and where applicable like reference numerals have been used to designatelike parts. In the arrangement shown in FIGURE 2, however, the pump 17is located outside the steam drum and is connected by feed and returnpipes 23 and 24 respectively to a fluid distributor box mounted o theinside of the false door 16.

The fluid distributor box is shown in detail in FIG- URES 3, 4 and 5 andcomprises connections 25 and 26 respectively for the feed and returnpipes 23 and 24. The connection 25 communicates with the distributor boxproper 27 which has a plurality (in this case six) of outlets 28. Theoutlets 28 are adapted for connection to the flexible tubes 22 by whichthe cleaning fluid is introduced into the downcomers 13.

The exhaust connection 26 is adapted for connection to a pipe 29 whichextends along the lower part of the steam drum and serves to return tothe pump the cleaning fluid after the latter has been circulated back tothe steam drum through the side wall and the rear wall tubes 14 and 15.

Here again all that is necessary to effect cleaning of the boiler systemis temporarily to replace the normal door of the steam drum 10 with thefalse door 16 and set the pump in operation for as long as may benecessary to efifect proper cleaning of the system. The cleaning fluidis drawn from the steam drum, into which it is introduced for thecleaning operation, circulated through the system, returned to the steamdrum and re-circulated as long as the pump is in operation.

Various arrangements may be provided for securing the false door inposition but one convenient arrangement comprises an over centre cam orlike clamping arrangement.

We claim:

1. Apparatus for chemically cleaning the internal surfaces of Water tubeboilers and the like by artifically i creating a normal fluidcirculation therein, said boilers having an upper drum portion having afirst opening therein, a lower drum portion having a second accessopening therein for the removal of sludge and a plurality of downcomersand risers coupling said lower and upper drum portions, said cleaningapparatus comprising:

a false door adapted to be applied to said first opening in said upperdrum portion of the boiler to be cleaned;

a pump coupled to said false door;

a manifold associated with said pump and adapted to be located withinsaid boiler;

a first plurality of flexible pipes, one end of each of said firstplurality of pipes being coupled to the output port of said pump viasaid manifold, the other ends of said first plurality of pipes beinginserted into said downcomers of the boiler system to produce pressureand a high velocity fluid stream in the downcomers; and

a second plurality of flexible pipes, one end of each of said secondplurality of pipes being coupled to the inlet port of said pump via saidmanifold, the other ends of said second plurality of pipes being coupledto said risers for returning said cleaning fluid to said pump.

2. Apparatus as claimed in claim 1, wherein said manifold is mounted tothe inner face of said false door.

3. Apparatus as claimed in claim 1, wherein said pump is mounted on theinner face of said false door.

4. Apparatus as claimed in claim 1, wherein said pump is provided with apressure fluid driving motor.

References Cited UNITED STATES PATENTS 2,020,350 11/1935 Bertschinger134-104 X 2,387,324 10/1945 Glickman 134-22 2,458,333 1/1949 Brady134-24 S. LEON BASHORE, Primary Examiner A. D. KELLOGG, AssistantExaminer US. Cl. X.R.

